I have a theory. Often I need to bolus before bed, I sleep on my side and I often wear omnipod on my arms (both). It is vertical, facing up. I have had absorption issues randomly.
Last night I was 244 and ready to go to bed. I didn't see it coming, because my Dexcom was 100 points off. I bolused a 4 (120 points for me). I woke up 4 hours later and I was still 244. I bolused again, rolled over, and by morning it was normal. Why didn't it work the first time? I have a theory. I rolled over and gravity lent a hand.
I am wearing my pod on the inside of my right arm. When I slept on my left side initially, it hung, and I didn't receive my bolus....it didn't absorb. When I rolled over, took another bolus, and my pod tucked in, gravity lent a hand and it absorbed fine.
I don't think we need to stay in the position forever, only long enough for the bolus to absorb.
I think this may help me understand why an infant and me, a 54 year old woman, both can have absorption problems with the same length of tubing.
I think as we all try new sites, we need to either wear wraps to hold it in place, or pay attention to our positions, the site positions and 'gravity'.
I have decided to not change my pods at bedtime, only when I can test and keep an eye on my #'s (not on a CGM.) The random highs from absorption or air bubbles or gravity or the full moon are too frustrating.
It sure does seem like it is the moon sometimes! :-) I think that my gravity theory is a little mechanical and a little position/site. My husband came up with a good analogy on the mechanical side. If I hold a garden hose straight up, and turn on the water for 5 seconds and compare it to the amount of water that the garden hose can squirt if I hold it vertically down; there will be a difference. Mechanically, does the pod know how much insulin is running through it or is it just performing the bolus operation for the allotted time? Am I trying to tell the 'hose' to squirt insulin up?
In addition, I think there is a site/position component to absorption. I don't always pay attention to the 'process'. I tell my pdm to deliver a bolus, I tell it how much, I stick it in my pocket and wait for it to stop clicking. I assume everything happened as planned. I am surprised when I check my numbers a couple of hours later, and it didn't make the difference I was anticipating.
I know that the site location chart shows us to place the pod horizontally on certain spots and vertically on others.Sites I also know that I am not always vertical, horizontal, etc. at the exact time I take my bolus.
I am going to pay closer attention to my position and the position of the pod on my body....when I take my boluses, to make sure that my pod is fully against my body the entire time and soon thereafter, and my 'garden hose' isn't trying to shoot anywhere but down.
Other than a bad site with consistently poor numbers, I don't notice a pattern. It is more of a random scenario which makes me hesitant to point to pod placement. If there is a steady rise, you can suspect any number of situations...old insulin, site inflammation, for instance, but the roller coaster is more frustrating. Maybe the garden hose sputters? I will be anxious to hear your research results!